B saw this idea in his Highlights High Five Magazine and wanted to try it.
To make a sponge finger puppet, cut a hole in the bottom of the sponge to fit your finger. Cut different shapes from construction paper and glue them on. That's it! Simple and easy.
I think this would be an interesting way to make puppets of characters from a story and retell it (I'm thinking Goldilocks and the Three Bears, Three Little Pigs, etc.).